What is Gii
Gii is an automatic code generation tool introduced in Yii 2.0. Code generation in Gii is quiet easy as filling the right information as per the instructions.
# Starting Gii
By default, Gii is always enabled in the developing mode due to following code in the entry script web/index.php file in Yii:
defined('YII_ENV') or define('YII_ENV', 'dev');
This is the Gii output. From here you can generate your codes automatically.